import {
	PDFLinkService
} from 'pdfjs-dist/es5/web/pdf_viewer';
var pendingOperation = Promise.resolve();
export default function (PDFJS) {
	function isPDFDocumentLoadingTask(obj) {
		return typeof (obj) === 'object' && obj !== null && obj.__PDFDocumentLoadingTask === true;
		// or: return obj.constructor.name === 'PDFDocumentLoadingTask';
	}
	function createLoadingTask(src, options) {
		var source;
		if (typeof (src) === 'string')
			source = { url: src };
		else if (src instanceof Uint8Array)
			source = {data: src};
		else if (typeof (src) === 'object' && src !== null)
			source = Object.assign({}, src);
		else
			throw new TypeError('invalid src type');
		// source.verbosity = PDFJS.VerbosityLevel.INFOS;
		// source.pdfBug = true;
		// source.stopAtErrors = true;
		if (options && options.withCredentials)
			source.withCredentials = options.withCredentials;
		var loadingTask = PDFJS.getDocument(source);
		loadingTask.__PDFDocumentLoadingTask = true; // since PDFDocumentLoadingTask is not public
		if (options && options.onPassword)
			loadingTask.onPassword = options.onPassword;
		if (options && options.onProgress)
			loadingTask.onProgress = options.onProgress;
		return loadingTask;
	}
	function PDFJSWrapper(canvasElt, annotationLayerElt, emitEvent) {
		var pdfDoc = null;
		var pdfPage = null;
		var pdfRender = null;
		var canceling = false;
		canvasElt.getContext('2d').save();
		function clearCanvas() {
			canvasElt.getContext('2d').clearRect(0, 0, canvasElt.width, canvasElt.height);
		}
		function clearAnnotations() {
			while (annotationLayerElt.firstChild)
				annotationLayerElt.removeChild(annotationLayerElt.firstChild);
		}
		this.destroy = function () {
			if (pdfDoc === null)
				return;
			// Aborts all network requests and destroys worker.
			pendingOperation = pdfDoc.destroy();
			pdfDoc = null;
		}
		this.getResolutionScale = function () {
			return canvasElt.offsetWidth / canvasElt.width;
		}
		this.printPage = function (dpi, pageNumberOnly) {
			if (pdfPage === null)
				return;
			// 1in == 72pt
			// 1in == 96px
			var PRINT_RESOLUTION = dpi === undefined ? 150 : dpi;
			var PRINT_UNITS = PRINT_RESOLUTION / 72.0;
			var CSS_UNITS = 96.0 / 72.0;
			var printContainerElement = document.createElement('div');
			printContainerElement.setAttribute('id', 'print-container')
			function removePrintContainer() {
				printContainerElement.parentNode.removeChild(printContainerElement);
			}
			new Promise(function (resolve, reject) {
				printContainerElement.frameBorder = '0';
				printContainerElement.scrolling = 'no';
				printContainerElement.width = '0px;'
				printContainerElement.height = '0px;'
				printContainerElement.style.cssText = 'position: absolute; top: 0; left: 0';
				window.document.body.appendChild(printContainerElement);
				resolve(window)
			})
					.then(function (win) {
						win.document.title = '';
						return pdfDoc.getPage(1)
								.then(function (page) {
									var viewport = page.getViewport({
										scale: 1
									});
									printContainerElement.appendChild(win.document.createElement('style')).textContent =
											'@supports ((size:A4) and (size:1pt 1pt)) {' +
											'@page { margin: 1pt; size: ' + ((viewport.width * PRINT_UNITS) / CSS_UNITS) + 'pt ' + ((viewport.height * PRINT_UNITS) / CSS_UNITS) + 'pt; }' +
											'}' +
											'#print-canvas { display: none }' +
											'@media print {' +
											'body { margin: 0 }' +
											'#print-canvas { page-break-before: avoid; page-break-after: always; page-break-inside: avoid; display: block }' +
											'body > *:not(#print-container) { display: none; }' +
											'}' +
											'@media screen {' +
											'body { margin: 0 }' +
											'}'
									return win;
								})
					})
					.then(function (win) {
						var allPages = [];
						for (var pageNumber = 1; pageNumber <= pdfDoc.numPages; ++pageNumber) {
							if (pageNumberOnly !== undefined && pageNumberOnly.indexOf(pageNumber) === -1)
								continue;
							allPages.push(
									pdfDoc.getPage(pageNumber)
											.then(function (page) {
												var viewport = page.getViewport({
													scale: 1
												});
												var printCanvasElt = printContainerElement.appendChild(win.document.createElement('canvas'));
												printCanvasElt.setAttribute('id', 'print-canvas')
												printCanvasElt.width = (viewport.width * PRINT_UNITS);
												printCanvasElt.height = (viewport.height * PRINT_UNITS);
												return page.render({
													canvasContext: printCanvasElt.getContext('2d'),
													transform: [ // Additional transform, applied just before viewport transform.
														PRINT_UNITS, 0, 0,
														PRINT_UNITS, 0, 0
													],
													viewport: viewport,
													intent: 'print'
												}).promise;
											})
							);
						}
						Promise.all(allPages)
								.then(function () {
									win.focus(); // Required for IE
									if (win.document.queryCommandSupported('print')) {
										win.document.execCommand('print', false, null);
									} else {
										win.print();
									}
									removePrintContainer();
								})
								.catch(function (err) {
									removePrintContainer();
									emitEvent('error', err);
								})
					})
		}

		this.renderPage = function (rotate) {
			if (pdfRender !== null) {
				if (canceling)
					return;
				canceling = true;
				pdfRender.cancel();
				// pdfRender.cancel().catch(function (err) {
				// 	emitEvent('error', err);
				// });
				return;
			}
			if (pdfPage === null)
				return;
			var pageRotate = (pdfPage.rotate === undefined ? 0 : pdfPage.rotate) + (rotate === undefined ? 0 : rotate);
			var scale = canvasElt.offsetWidth / pdfPage.getViewport({
				scale: 1
			}).width * (window.devicePixelRatio || 1);
			var viewport = pdfPage.getViewport({
				scale: scale,
				rotation: pageRotate
			});
			emitEvent('page-size', viewport.width, viewport.height, scale);
			canvasElt.width = viewport.width;
			canvasElt.height = viewport.height;
			pdfRender = pdfPage.render({
				canvasContext: canvasElt.getContext('2d'),
				viewport: viewport
			});
			annotationLayerElt.style.visibility = 'hidden';
			clearAnnotations();
			var viewer = {
				scrollPageIntoView: function (params) {
					emitEvent('link-clicked', params.pageNumber)
				},
			};
			var linkService = new PDFLinkService();
			linkService.setDocument(pdfDoc);
			linkService.setViewer(viewer);
			pendingOperation = pendingOperation.then(function () {
				var getAnnotationsOperation =
						pdfPage.getAnnotations({
							intent: 'display'
						})
								.then(function (annotations) {

									PDFJS.AnnotationLayer.render({
										viewport: viewport.clone({
											dontFlip: true
										}),
										div: annotationLayerElt,
										annotations: annotations,
										page: pdfPage,
										linkService: linkService,
										renderInteractiveForms: false
									});
								});
				var pdfRenderOperation =
						pdfRender.promise
								.then(function () {
									annotationLayerElt.style.visibility = '';
									canceling = false;
									pdfRender = null;
								})
								.catch(function (err) {
									pdfRender = null;
									if (err instanceof PDFJS.RenderingCancelledException) {
										canceling = false;
										this.renderPage(rotate);
										return;
									}
									emitEvent('error', err);
								}.bind(this))
				return Promise.all([getAnnotationsOperation, pdfRenderOperation]);
			}.bind(this));
		}
		this.forEachPage = function (pageCallback) {
			var numPages = pdfDoc.numPages;
			(function next(pageNum) {
				pdfDoc.getPage(pageNum)
						.then(pageCallback)
						.then(function () {
							if (++pageNum <= numPages)
								next(pageNum);
						})
			})(1);
		}
		this.loadPage = function (pageNumber, rotate) {
			pdfPage = null;
			if (pdfDoc === null)
				return;
			pendingOperation = pendingOperation.then(function () {
				return pdfDoc.getPage(pageNumber);
			})
					.then(function (page) {
						pdfPage = page;
						this.renderPage(rotate);
						emitEvent('page-loaded', page.pageNumber);
					}.bind(this))
					.catch(function (err) {
						clearCanvas();
						clearAnnotations();
						emitEvent('error', err);
					});
		}
		this.loadDocument = function (src) {
			pdfDoc = null;
			pdfPage = null;
			emitEvent('num-pages', undefined);
			if (!src) {
				canvasElt.removeAttribute('width');
				canvasElt.removeAttribute('height');
				clearAnnotations();
				return;
			}
			// wait for pending operation ends
			pendingOperation = pendingOperation.then(function () {
				var loadingTask;
				if (isPDFDocumentLoadingTask(src)) {
					if (src.destroyed) {
						emitEvent('error', new Error('loadingTask has been destroyed'));
						return
					}
					loadingTask = src;
				} else {
					loadingTask = createLoadingTask(src, {
						onPassword: function (updatePassword, reason) {
							var reasonStr;
							switch (reason) {
								case PDFJS.PasswordResponses.NEED_PASSWORD:
									reasonStr = 'NEED_PASSWORD';
									break;
								case PDFJS.PasswordResponses.INCORRECT_PASSWORD:
									reasonStr = 'INCORRECT_PASSWORD';
									break;
							}
							emitEvent('password', updatePassword, reasonStr);
						},
						onProgress: function (status) {
							var ratio = status.loaded / status.total;
							emitEvent('progress', Math.min(ratio, 1));
						}
					});
				}
				return loadingTask.promise;
			})
					.then(function (pdf) {
						pdfDoc = pdf;
						emitEvent('num-pages', pdf.numPages);
						emitEvent('loaded');
					})
					.catch(function (err) {
						clearCanvas();
						clearAnnotations();
						emitEvent('error', err);
					})
		}
		annotationLayerElt.style.transformOrigin = '0 0';
	}
	return {
		createLoadingTask: createLoadingTask,
		PDFJSWrapper: PDFJSWrapper,
	}
}